Field of the Invention
The present invention relates to a heat exchanger, particularly for motor vehicles.
Description of the Background Art
Heat exchangers are sufficiently known from the conventional art. In this regard, tube bundles of flat tubes are usually provided, whereby the tube ends extend through openings into a collecting tank and are there soldered to the collecting tank. Cracks, therefore failures, occur in the area of the tube/tank connection with thermal cycling or in the case of thermal stress due to tension/compression. It becomes apparent that the failures usually occur on the narrow side of the tube at the tube/tank connection.
DE 2839142, which corresponds to U.S. Pat. No. 4,269,267, provides that oval tubes are used in a heat exchanger, whereby the long tube side walls are braced elastically and thereby form an inwardly curved concave side wall.